Short answers, pulled from the story.
Ginger originated in Maritime Southeast Asia and was first domesticated by the Austronesian peoples. It is a true cultigen and does not exist in a wild state. The Austronesians carried it across the Indo-Pacific during their expansion starting around 5,000 years before the present, reaching as far as Hawaii.
The earliest written record of ginger appears in the Analects, written by the disciples of Confucius during China's Warring States period, between 475 and 221 BCE. The text states that Confucius ate ginger with every meal.
India is the largest producer of ginger in the world. In 2023, world production of raw ginger was 4.9 million tonnes, and India accounted for 45% of that total. Nigeria and China are the next largest producers.
Ginger's flavor and fragrance come from volatile oils making up 1-3% of its fresh weight, primarily sesquiterpenes such as beta-bisabolene and zingiberene, along with gingerols, shogaols, and zingerone. The compound 6-gingerol is the major source of ginger's pungency. Some 400 chemical compounds exist in raw ginger in total.
The evidence is limited and mixed. Ginger may offer some benefit over placebo for nausea and vomiting during pregnancy, but that evidence is considered low quality. There is no good evidence that ginger helps with chemotherapy-induced nausea and vomiting. It remains uncertain whether ginger is effective for treating any disease.
Ginger was smuggled from Asia into the Caribbean islands sometime in the 16th century, at the encouragement of the Spanish Crown. Of the spices introduced at that time, including black pepper, cloves, and cinnamon, only ginger thrived. By the end of the 16th century it had become the leading export crop on both Hispaniola and Puerto Rico, displacing sugar.